This is a continuation of a program for the study of clinical, neurolinguistic, and neuroanatomic aspects of aphasia. The long-term objectives are to advance the understanding of the mechanisms of normal language and their neural basis so as to develop a coherent view of how the symptomatology of aphasia relates to the injury of particular brain structures and the consequent modification of linguistic and cognitive capacities. A concurrent goal is to apply developing theoretical insights to a rationally based diagnostic assessment and treatment of aphasia. Specific goals in the proposed project period and methods of accomplishing them are: 1. to investigate disorders of sentence comprehension and sentence production in terms of the explanatory power of specific cognitive and linguistic principles. 2. to study word production and word comprehension with techniques that probe the unfolding of these processes and their breakdown in real time. 3. to compare the comprehension of discourse -- particularly pragmatic aspects -- in aphasic and right brain damaged subjects. 4. to examine the cognitive basis for the success of global aphasics in mastering a nonverbal computerized communication system. 5. to study changes in attentional functions, associated with frontal lobe lesions and how they modify aphasic symptoms due to left temporal lobe lesions.